Positive drive fin



FIG. 1 is a top perspective view of a positive drive fin showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a front elevational view thereof;

FIG. 7 is a rear elevational view thereof;

FIG. 8 is a sectional view taken along line 8—8 of FIG. 3; and,

FIG. 9 is a sectional view taken along line 9—9 of FIG. 3. 

The ornamental design for a positive drive fin, as shown and described. 